This invention relates to valve constructions and particularly to a valve assembly which has utilization in handling corrosive fluids. Valve assemblies of this general nature are known, as for instance, those constructed of highly corrosion resistant materials so that the fluids directly contacting such components will not cause corrosion and potential failure thereof. Utilization of sophisticated metal materials for this purpose may, however, involve complex machining in addition to material cost factors and their use may still necessitate the tailoring of particular materials to particular fluid applications. It accordingly is also known to form all or at least major components of valve assemblies from substantially inert plastic resin materials such as polyethylene, polypropylene and fluoroethylene polymers such as Teflon. Valves constructed of plastic may, however, lack the necessary tolerance and strength characteristics required and, accordingly, a need exists for an improved valve assembly wherein normally utilized non-sophisticated metal components thereof are shielded from contact with corrosive fluids during the operation thereof.
Inasmuch as valves of this type are often utilized in inaccessible locations and are actuated by remote control, it is particularly necessary that any protective element not only effectively shield the metal working components of the valve from corrosion, but also does not interfere with reliable valve operation. An example of the overall type environment in which valves of this nature may be utilized is set forth in U.S. Pat. No. 3,884,446 issued May 20, 1975 and assigned to the G. W. Dahl Company, Inc., Bristol, RI. Therein disclosed is a control valve actuator which has utility in actuating the present valve assembly and accordingly the disclosure thereof is hereby specifically incorporated by reference into the present application.